Justin and Hailey are spending their Turkey Day in Miami, grabbing juice at Joe & The Juice together to start off their holiday ... and ya gotta check out the shirt on Justin's back.

As you can see ... Justin's threads say, "Drop the album already."

Is it a sign Justin's getting ready to bless his fans with some R&Bieber?!? Then again, maybe he just likes the shirt -- it's from his fashion line after all.

As we first told you ... JB's planning a new tour and practicing his dance moves. We've been told the tour will coincide with a new album, which he's teasing as a transition into R&B.

Oh, and get this ... Justin's going with platinum blonde hair ... he debuted some pink hair earlier this week, but he's already switched to platinum.